CN111944146B

CN111944146B - Poly-triazole resin containing polyphenyl, composite material thereof and preparation method

Info

Publication number: CN111944146B
Application number: CN201910410520.2A
Authority: CN
Inventors: 黄发荣; 万里强; 王海军; 王露雨; 张俊; 马明明
Original assignee: East China University of Science and Technology
Current assignee: East China University of Science and Technology
Priority date: 2019-05-16
Filing date: 2019-05-16
Publication date: 2022-10-14
Anticipated expiration: 2039-05-16
Also published as: CN111944146A

Abstract

The invention discloses a polytriazole resin containing polyphenyl, a composite material thereof and a preparation method of the polytriazole resin. The resin is a copolymer prepared by 1, 3-dipolar cycloaddition reaction of tetra- (4-propargyloxybenzene) ethylene and 4,4' -biphenyl dimethyl azide; the molar ratio of alkynyl to azido is 1 to 1.3. The resin can be prepared into the resin composite material by a mould pressing forming method. The resin is prepared by 1, 3-dipolar cycloaddition reaction, the reaction is efficient, the temperature is lower, and the condition is mild; the obtained resin has excellent processing performance, can be crosslinked and cured at the temperature of 60-80 ℃, the cured product has excellent mechanical property and heat resistance, the bending strength of the T700 unidirectional carbon fiber reinforced composite material reaches 1450-1500 MPa, the bending modulus is 140-145 GPa, the interlayer shear strength is 50-55 MPa, and the resin is expected to be widely applied as a resin matrix of aerospace structural materials and the like.

Description

Poly-triazole resin containing polyphenyl, composite material thereof and preparation method

Technical Field

The invention relates to a polytriazole resin containing polyphenyl, a composite material thereof and a preparation method thereof.

Background

The polytriazole resin is a high-performance resin which is formed by carrying out 1, 3-dipolar cycloaddition reaction on a polyazide compound and an alkynyl compound to form a resin with a main chain structure containing a 1,2, 3-triazole ring. The polytriazole resin has good processing performance, and the resin formed by curing has good heat resistance and thermal stability at a low temperature (60-80 ℃).

In 1893, michael [ Michael A.. J Parkt Chem,1893 (48): 94] found that 1, 3-dipolar cycloaddition of an azide compound to an alkynyl compound at 60 to 80 ℃ can form a compound containing 1, 4-disubstituted and 1, 5-disubstituted-1, 2, 3-triazole rings, the reaction formula of which is as follows:

in the late 60's of the 20 th century, johnson et al discovered that compounds having both azido and alkynyl groups in their molecular structures could undergo intramolecular 1, 3-dipolar cycloaddition to produce linear polymers having a 1,2, 3-triazole ring in their main chain, which polymers had good thermal stability [ [1 ] 1]K.E Johnson,J.A.Lovinger,C.O.Parker,et al.,Polym Lett,1966,4(12),977；[2]M.G.Baldwin,K.E.Johnson,J.A.Lovinger,et al.,Polym Lett,1967,5(11),803]. In the 80's of the 20 th century, mock et al found that 1, 3-dipolar cycloaddition of azido-alkynyl groups catalyzed by some amino-bearing reagents resulted in only 1, 4-substituted triazole ring structures. In 2002, huangfa Rong laboratory, university of east China's university, started studying the reaction of alkyne and azide and utilized the thermal reaction of alkyne and azide to prepare polytriazole resins. In the same year, sharpless et al reported that a 1, 3-dipolar cycloaddition reaction of an azido-alkynyl group catalyzed by a cuprous salt (CuI) was found to increase the rate of the catalyzed addition reaction by 10 ⁶ And stereoselectivity, yielding only 1, 4-disubstituted 1,2, 3-triazole compounds, sharpless proposed the Click chemistry concept.

In recent years, more and more researchers have designed novel polymers by utilizing click reaction of alkyne and azide, and prepared high-molecular prepolymers, in particular, design and functionalization of branched polymers, surface modification and the like.

East China University of TechnologyDulie, huang Fang et al use 1, 3-dipolar cycloaddition reaction of azido and alkynyl at low temperature to prepare polytriazole resin, which has excellent processability and can be cured and formed at low temperature, and the cured resin and resin composite material have excellent mechanical properties and good thermal properties, but are still insufficient in the field of higher use temperature. For example [ Du Lei, huang Hui Rong, hu Yan hong, qi Hui Min, etc. ], ZL200510000962.8 (2005-5-8)]A is disclosed ₂ B ₄ Polytriazole resins of the type in which A is BAMBP, 4' -biphenyldimethylazide ₂ B ₄ The heat resistance of polytriazole resins of the type is still inadequate, in particular with respect to the glass transition temperature T _g In other words (DMA test common mode, there are three-point bending mode, single cantilever, double cantilever mode and stretching mode, generally the stretching mode is adopted for film material and rubber material, and T of polytriazole resin _g About 30 ℃ higher in tensile mode than in the double cantilever mode), T, if tested in tensile mode _g At 250 c, but if tested in the dual cantilever mode according to an embodiment of the invention, T _g Only about 220 ℃; 5wt% thermal weight loss temperature T of resin condensate _d5 The temperature was 350 ℃. [ Wan L, luo Y, xue L, et al preparation and properties of a novel polytriazole resin [ J].Journal of Applied Polymer Science,2007,104(2):1038-1042.]A is disclosed ₂ ’B ₄ Polytriazole resins of the type in which A' is XDA p-xylylazide, the said A ₂ ’B ₄ The heat resistance of polytriazole resins of the type is still inadequate, in particular with respect to the glass transition temperature T _g In other words, if tested according to the tensile mode method, T _g Only 218 ℃; 5wt% thermal weight loss temperature T of resin condensate _d5 The temperature was 350 ℃.

For A ₂ B ₄ Although the mechanical properties of the resin are satisfactory, the heat resistance is insufficient, and how to solve the problem A ₂ B ₄ The heat resistance of resin is still a problem to be solved.

Disclosure of Invention

The technical problem to be solved by the invention is to overcome the problem of A in the prior art ₂ B ₄ Type (difunctional azide and tetraalkynyl polymerization) resin system heat resistanceThe performance of the resin is still insufficient, and a polytriazole resin containing polyphenyl, a composite material thereof and a preparation method are provided.

The invention solves the technical problems through the following technical scheme.

The invention provides a polytriazole resin containing polyphenyl, which is a copolymer prepared by performing 1, 3-dipolar cycloaddition reaction on tetra- (4-propargyloxystyrene) ethylene (TPOBE) and 4,4' -biphenyl dimethyl azide (BAMBP);

wherein the structural formula of the tetra- (4-propargyloxystyrene) is shown as follows:

the structural formula of the 4,4' -biphenyl dimethyl azide is shown as follows:

the molar ratio of alkynyl to azido is (1.0-1.30): 1.0.

In the present invention, the molar ratio of the alkynyl group to the azido group is preferably (1.02 to 1.10): 1.0, for example 1.02. As is known in the art, the alkynyl group is derived from TPOBE,1mol of TPOBE contains 4mol of alkynyl group; the azide group is derived from BAMBP, and 1mol of BAMBP contains 2mol of azide group.

In the invention, the structure of the poly-benzene-containing polytriazole resin is shown as the formula I:

wherein, the first and the second end of the pipe are connected with each other,

in the present invention, the glass transition temperature T of the cured product of the polytripolytriazole-containing resin _g It may be 250 to 255 deg.C, for example 251 deg.C.

In the invention, the polytriazole resin containing the polyphenyl is easy to dissolve in acetone, THF, a chlorohydrocarbon solvent, DMF, DMSO and other strong polar solvents.

In the invention, the processing window of the poly-benzene-containing triazole resin is wider and can be between 36 and 102 ℃.

In the invention, the density of the polyphenyl-containing polytriazole resin after being completely cured can be 1.2-1.3 g/cm ³ For example 1.2263g/cm ³ 。

In the present invention, the crosslinking density of the polyphenylene-containing polytriazole resin after complete curing may be 6.9-7.0X 10 ^- ³ mol/cm ³ E.g. 6.92 x 10 ^-3 mol/cm ³ 。

In the present invention, the cured product of the polytriazole resin with benzene has a 5wt% thermal weight loss temperature T _d5 It may be 360 to 365 deg.C, for example 360 deg.C.

In the present invention, the cured product of the cast product of the polyterpolytriazole-containing resin may have a flexural strength of 120 to 126MPa, for example, 122.3MPa, and a flexural modulus of 2.4 to 3.0GPa, for example, 2.7GPa.

The invention also provides a preparation method of the polyphenyl-containing polytriazole resin, which comprises the following steps:

1) Reacting tetra- (4-hydroxystyrene) ethylene (TPE-OH) with bromopropyne under the alkaline condition in the presence of a water-soluble organic solvent to obtain the tetra- (4-propargyloxystyrene) ethylene (TPOBE);

the structural formula of the tetra- (4-hydroxystyrene) ethylene is as follows:

2) In the presence of an organic solvent, the tetra- (4-propargyloxybenzene) ethylene and the 4,4' -biphenyl dimethyl azide react to prepare the polytriazole resin containing the polyphenyl.

In step 1), the alkaline condition may be a condition that is conventional in the chemical field and can make the reaction system alkaline, and may be achieved by adding one or more of potassium carbonate, sodium carbonate and sodium hydroxide, preferably by adding potassium carbonate.

In step 1), the organic solvent may be a water-soluble solvent capable of dissolving the raw materials, which is conventional in the chemical field, and may be, for example, DMAc and/or DMF.

In the step 1), the structural formula of the tetra- (4-hydroxystyrene) ethylene is as follows:

it can be obtained by the following reaction: reference documents: ZHao L, chen Y, yuan J, et al, electrospan fibre materials with a Conjugated polyphenylethylene and a Mannose for a Sensitive Turn-On Fluorescent Sensing of Escherichia coli [ J].Acs Appl Mater Interfaces,2015,7(9):5177-5186.

In step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the base used under basic conditions may be conventional in the art, and is preferably 1.0 (4.0 to 8.0), more preferably 1.0.

In step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the bromopropyne can be conventional in the art, and is preferably 1.0 (4.2-5.2), more preferably 1.0.

In the step 1), the operation and conditions of the reaction can be the operation and conditions of the reaction which are conventional in the field, and the reaction is generally carried out after the bromopropyne is dropwise added at normal temperature. The reaction temperature is preferably 60 to 80 ℃, more preferably 70 ℃. The reaction time is preferably 20 to 30 hours, for example 24 hours.

In step 1), after the reaction is completed, post-treatment is preferably performed. The operations and conditions of the said work-up can be conventional in the art and are preferably carried out as follows: after removing excessive salt, standing the obtained filtrate in water for precipitation, filtering to obtain a crude product, and recrystallizing the crude product.

The operation and conditions for removing the excess salt may be conventional in the art, and may be generally performed by suction filtration. The water is generally deionized water. The operation and conditions of the filtration can be conventional in the art, and generally can be performed by suction filtration. The operation and conditions for the recrystallization may be conventional in the art, and it is preferable to perform the recrystallization using methanol. The tetra- (4-propargyloxystyrene) obtained after the recrystallization is generally a pale yellow solid.

In the step 1), the melting point of the tetra- (4-propargyloxystyrene) ethylene is 164-165 ℃.

In step 2), the organic solvent may be an organic solvent which is conventional in the art and can dissolve the raw material and has a boiling point below 80 ℃, for example, acetone and/or THF may be selected.

In the step 2), the total mass of the tetra- (4-propargyloxystyrene) and the 4,4' -biphenyldimethylazide is preferably 25 to 50 percent, more preferably 50 percent, of the total mass of the reaction solution.

In step 2), the reaction conditions may be those conventional in the art for such reactions. The reaction conditions are preferably: the temperature is 60-70 ℃, the time is 1-6 h, and the reaction is better for 1.5h at 70 ℃.

In the step 2), after the reaction result, the reaction solution is preferably cooled to room temperature.

The invention also provides a polyphenyl-containing polytriazole resin composite material, and the raw materials of the polyphenyl-containing polytriazole resin composite material are the polyphenyl-containing polytriazole resin.

In the present invention, the polybenzazole resin composite can be prepared by a method conventional in the art for composite materials, such as a press molding method.

The invention also provides a preparation method of the polyphenyl-containing polytriazole resin composite material, which comprises the following steps:

1) Impregnating a reinforcing fiber with the solution containing the polyphenyl polytriazole resin to prepare a prepreg;

2) And removing the solvent from the prepreg, and carrying out mould pressing, curing and forming to obtain the polyphenyl-triazole-containing resin composite material.

In step 1), the concentration of the polybenzazole resin in the solution may be conventional in the art, and is preferably 35 to 40% by weight. The solvent employed in the solution may be conventional in the art and may typically be tetrahydrofuran and/or acetone.

In step 1), the reinforcing fibers may be reinforcing fibers conventionally used in the art for the preparation of composite materials, typically carbon fibers or quartz fibers, preferably unidirectional carbon fibers T700, such as the japanese dongli T700SC model.

In step 1), the operation and conditions of the impregnation may be conventional in the art.

In step 2), the prepreg can be stacked to a desired height and then subjected to solvent removal operation, as required.

In step 2), the solvent removal operation and conditions may be conventional in the art and are generally performed in a vacuum oven.

In step 2), before the operation of mold pressing, curing and molding, air in the prepreg is preferably removed, and the prepreg is generally degassed at 80 ℃.

In step 2), the operation and conditions of the press-molding, curing and forming can be conventional in the art and are generally carried out on a press vulcanizer. The temperature for the mold pressing, curing and molding is preferably 80 to 200 ℃, for example, 80 ℃,120 ℃, 150 ℃ or 180 ℃. The time for the die pressing curing molding is preferably 12 to 18 hours. The pressure for the press-molding curing molding is preferably 0.6 to 1MPa, for example, 0.8MPa. The operation of the mold pressing solidification molding is generally to solidify and mold at about 80 ℃ and then completely solidify at higher temperature, and preferably comprises the following steps: the mixture is firstly molded by heat preservation for 12 hours at 80 ℃ under the pressure of 0.8MPa, and then is completely cured by heat preservation for 2 hours at 120 ℃,2 hours at 150 ℃ and 2 hours at 180 ℃ in sequence under normal pressure.

The invention also provides a polyphenyl-containing polytriazole resin composite material prepared by the preparation method.

The flexural strength of the polyphenyl-triazole-containing resin composite material can be 1450-1500 MPa, such as 1454MPa, the flexural modulus can be 140-145 GPa, such as 143.5GPa, and the interlaminar shear strength can be 50-55 MPa, such as 50.55MPa.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows:

the resin is prepared by 1, 3-dipolar cycloaddition reaction (click reaction) of azide and alkynyl, the reaction is very efficient, the required temperature is lower (compared with other thermosetting resins), and the forming required condition is mild; the synthesis process is simple and easy to implement, and the cost of raw materials and the synthesis process is low; the synthesized polyphenyl-containing polytriazole resin is brown liquid, has excellent processing performance, can be polymerized, crosslinked and cured at the temperature of 60-80 ℃, and has excellent mechanical properties and better heat resistance of cured products.

The poly-triazole resin containing polyphenyl has excellent processing performance, mechanical property and heat resistance, and the glass transition temperature (T) of a condensate of the poly-triazole resin containing polyphenyl has excellent processing performance, mechanical property and heat resistance _g ) Can reach 250-255 ℃ and the thermal weight loss temperature (T) _d5 ) The T700 unidirectional carbon fiber reinforced composite material can reach 360-365 ℃, the bending strength can reach 1450-1500 MPa, the bending modulus can reach 140-145 GPa, the interlaminar shear strength can reach 50-55 MPa, and the composite material is expected to be widely applied as a resin matrix of aerospace structural materials and the like.

Drawings

FIG. 1 shows TPE-OH and TPOBE of example 1 ¹ H-NMR spectrum.

FIG. 2 is the FT-IR spectrum of TPE-OH and TPOBE in example 1, wherein FIG. 2a is the FT-IR spectrum of TPE-OH and FIG. 2b is the FT-IR spectrum of TPOBE.

FIG. 3 shows EI-MS spectra of TPE-OH and TPOBE in example 1, wherein FIG. 3a shows EI-MS spectra of TPE-OH, and FIG. 3b shows EI-MS spectra of TPOBE.

FIG. 4 is an infrared spectrum of mPTA resin of example 1 at different stages of curing, wherein 0 represents the infrared spectrum of mPTA resin after removing the solvent from the brown liquid obtained in step (3); 1 is an infrared spectrogram of a product obtained after the mPTA resin is subjected to heat preservation at 80 ℃ for 12 hours after the solvent is removed; 2 is an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours and then carrying out heat preservation at 120 ℃ for 2 hours; 3 is an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours, then carrying out heat preservation at 120 ℃ for 2 hours and carrying out heat preservation at 150 ℃ for 2 hours; and 4, an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours, then carrying out heat preservation at 120 ℃ for 2 hours, carrying out heat preservation at 150 ℃ for 2 hours and carrying out heat preservation at 180 ℃ for 2 hours.

FIG. 5 is a rheological curve of the polytriazole resin synthesized in example 1.

FIG. 6 is a DSC plot of the polytripolytriazole-containing resin synthesized in example 1 with the upward arrow representing the exotherm.

FIG. 7 is a DMA curve of a cured product of the polytriazole resin with benzene synthesized in example 1.

FIG. 8 is a TGA curve of a cured product of the polytriazole resin with benzene synthesized in example 1 under nitrogen, wherein the dashed line represents the 5wt% thermal weight loss of the cured product.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the invention thereto. Experimental procedures without specifying specific conditions in the following examples were selected in accordance with conventional procedures and conditions, or in accordance with commercial instructions.

The structure of tetra- (4-propargyloxystyrene) synthesized by the invention uses a hydrogen nuclear magnetic resonance spectrum ( ¹ H-NMR), infrared spectroscopy (FT-IR) and Mass Spectrometry (MS). Hydrogen nuclear magnetic resonance spectroscopy (NMR) ¹ H-NMR) Using a Bruker AVANCE 500 model high resolution Fourier transform nuclear magnetic resonance spectrometer, operating frequency 400MHz, solvent CDCl ₃ TMS is used as an internal standard; fourier Infrared Spectroscopy (FT-IR) analysis Using Nicolet 6700 Fourier Infrared Spectroscopy, KBr pellet method, from Nicolet, USA, scanning range 4000-400cm ^-1 Resolution of 0.09cm ^-1 And the number of scanning times is 32. Mass Spectrometry (MS) analysis electron impact mass spectrometry, instrument: EI-high resolution time-of-flight mass spectrometer of Waters corporation, USA is adopted for analysis; test conditions and methods: the mass-to-nucleus ratio m/z is in the range of 10 to 1500Da.

The processing performance of the resin is analyzed by the rheological behavior of the resin; the curing behaviour of the resin was characterized by Differential Scanning Calorimetry (DSC), test apparatus: the analysis adopts an American TA Q2000 differential scanning calorimetry analyzer, and the test conditions and the method are as follows: weighing a certain amount of powder sample (about 2 mg) into aluminum crucible, sealing with cover, and testing under nitrogenThe process is carried out in the atmosphere, the gas flow is 50mL/min, the heating rate is 10 ℃/min, and the temperature range is room temperature-300 ℃. The bending properties of the cured resin casting body and the resin composite material are tested by a three-point bending method; the thermal properties of the cured resin were analyzed by dynamic mechanical thermal analysis (DMA) and thermogravimetric analysis (TGA). Thermal Gravimetric Analysis (TGA) A thermal gravimetric analyzer model TGA/DSC 1LF of METTLER TOLEDO, switzerland was used, the temperature rise rate was 10 ℃/min, the temperature range was 40-800 ℃, and the flow rate of nitrogen was 60mL/min. Dynamic mechanical thermal analysis (DMA) adopts a dynamic mechanical thermal analyzer of Switzerland Mettler Toledo DMA 1 type; test conditions and methods: the temperature is measured in a double-cantilever mode, the heating rate is 3 ℃/min, the vibration frequency is 11Hz, and the temperature range is between room temperature and 350 ℃. Viscosity temperature rheological behavior is determined by using RheoStress RS600 type rotational rheometer of Thermo Hakke company, USA, with a heating rate of 3 deg.C/min and a shear rate of 0.01s ^-1 The temperature range is room temperature-200 ℃. Mechanical properties of cured resin casting bodies and resin composite materials are measured by using a Shenzhen New Miss material detection Limited SANS CMT 4204 type microcomputer-controlled electronic universal tester, 5-10 test sample bars are arranged in each group, and results are averaged. The resin casting was tested for flexural strength and flexural modulus according to GB/T2570-1995, with an experimental load rate of 2mm/min, with continuous loading during the experiment until the specimen failed.

The bending strength and the bending modulus of the unidirectional fiber reinforced resin composite material flat plate are tested according to GB/T3356-1999, the experimental loading speed is 2mm/min, and the test sample is continuously loaded to be damaged during the experiment. And testing the interlaminar shear strength of the unidirectional fiber reinforced resin composite flat plate according to JL/T773-2010, wherein the experimental loading speed is 2mm/min, and the unidirectional fiber reinforced resin composite flat plate is continuously loaded until a test sample is damaged during the experiment.

EXAMPLE 1 preparation of Polybenzotriazole-containing resin

(1) Synthesis of tetra- (4-hydroxystyrene) ethylene (TPE-OH)

4.87g of zinc powder and 100ml of THF were charged into a 250ml four-necked flask, 4.09ml of titanium tetrachloride was added dropwise at-10 ℃ under anhydrous conditions, and the mixture was refluxed for 3 hours, and 7.89g of 4, 4-dihydroxybenzophenone was added and the reaction was continued for 4 hours. After the reaction is finished, cooling to room temperature, adding 10% of ₂ CO ₃ Washing the solution, and filtering to obtain yellow filtrate. By using BExtracting with ethyl acetate, washing the organic phase with deionized water, and adding anhydrous Na ₂ SO ₄ Drying and removing the solvent to obtain a crude product. Recrystallizing the crude product with ethyl acetate to obtain a yellow solid product TPE-OH with the yield of 40 percent, the purity of 99.1 percent, the melting point of 323-324 ℃ and the literature value of 323-324 ℃. The synthesis reaction of TPE-OH is shown below:

(2) Preparation of tetra- (4-propargyloxystyrene) ethylene (TPOBE)

3.96g of TPE-OH and 6.62g of K ₂ CO ₃ 48g DMAc is added into a 100ml four-neck flask, stirred for 30 minutes at normal temperature, and 5.71g of bromopropyne, TPE-OH and K are dripped ₂ CO ₃ And bromopropyne at a molar ratio of 1.0:4.8:4.8 And reacting at 70 ℃ for 24 hours. After the reaction is finished, filtering to remove salt, pouring the organic phase into de-iced water, standing for precipitation, and filtering to obtain a crude product. Recrystallizing the crude product with methanol to obtain a light yellow solid product TPOBE with the yield of 90 percent, the purity of 97.9 percent and the melting point of 164-165 ℃; the specific reaction flow is as follows:

data of nuclear magnetic hydrogen spectrum, infrared spectrum and mass spectrum of tetra- (4-propargyloxyphenyl) ethylene (TPOBE):

¹ H-NMR(CDCl ₃ ,TMS)，δ(ppm)：3.53(t,4H,C-C≡CH),4.69(d,8H,O-CH ₂ ),6.75(d,8H,Ar-H),6.84(d,8H,Ar-H)。

FT-IR(KBr):3293cm ^-1 (≡C-H),2121cm ^-1 (C≡C),1603cm ^-1 (C＝C),1220cm ^-1 ,(Ar-O-CH ₂ )。

EI-MS(m/z):548.2(M ⁺ )。

FIG. 1 shows TPE-OH and TPOBE of example 1 ¹ H-NMR spectrum. In FIG. 1, the ratio of the peak areas of a: b: c: d is 1: c': e peak area ratio of1.00:1.00:0.5。

FIG. 2 shows FT-IR spectra of TPE-OH and TPOBE in example 1, wherein FIG. 2a shows FT-IR spectrum of TPE-OH, and FIG. 2b shows FT-IR spectrum of TPOBE.

(3) Preparation of polytriazole resin containing polyphenyl (mPTA)

TPOBE (5.1mmol, 2.80g), BAMBP (10.0 mmol, 2.64g) and THF (5.44 g) were added to a three-necked flask to prepare a solution having a solid content of 50% (molar ratio of alkynyl group to azido group: 1.02), and the mixture was stirred mechanically, condensed water was introduced, and reacted at 70 ℃ for 1.5 hours. After the reaction was complete, the reaction was cooled to room temperature to give a brown liquid mPTA resin.

FIG. 4 is an infrared spectrum of mPTA resin of example 1 at different stages of curing, wherein 0 represents the infrared spectrum of mPTA resin after removing the solvent from the brown liquid obtained in step (3); 1 represents an infrared spectrogram of a product obtained after the mPTA resin is subjected to heat preservation at 80 ℃ for 12 hours after the solvent is removed; 2, an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours and then carrying out heat preservation at 120 ℃ for 2 hours; 3 is an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours, then carrying out heat preservation at 120 ℃ for 2 hours and carrying out heat preservation at 150 ℃ for 2 hours; and 4, an infrared spectrogram of a product obtained by carrying out heat preservation on the mPTA resin after the solvent is removed at 80 ℃ for 12 hours, then carrying out heat preservation at 120 ℃ for 2 hours, carrying out heat preservation at 150 ℃ for 2 hours and carrying out heat preservation at 180 ℃ for 2 hours. As can be seen from FIG. 4, 3275cm in original curve 0 ^-1 The peak is a characteristic peak of ≡ C-H, 2096cm ^-1 Is represented by-N ₃ and-C.ident.C-. With increasing degree of cure, the ≡ C-H peak, -C ≡ C-peak and-N ₃ The peak gradually decreased. Curing at 80 deg.C/12 h, 3130cm ^-1 A C-H stretching vibration peak appears on the triazole ring, which indicates that the alkynyl compound and the azide react at 80 ℃ to generate 1, 3-dipolar cycloaddition reaction to generate the triazole ring. At 3275cm when the resin is cured to 120 DEG C ^-1 And 2096cm ^-1 The peak is greatly reduced. 3275cm when the resin was cured to 150 deg.C ^-1 And 2096cm ^-1 The peak is reduced continuously, which indicates that the blood is further developedAnd generating addition reaction. When the temperature is continuously increased to 180 ℃, the temperature is equal to C-H and-N ₃ And the characteristic peak of-C.ident.C almost completely disappeared, indicating that the curing of the resin system tended to be complete.

In fig. 4, the stretching vibration peak of-C = C-on the benzene ring not participating in the reaction in the curing process is used as an internal standard to calibrate the absorption peak intensity of the varying group, so that the reaction degree of the resin at different curing stages can be obtained. At 1504cm ^-1 The stretching vibration peak of-C = C-on the benzene ring at the vicinity is used as the internal standard of the measurement, because 2096cm ^-1 vicinity-N ₃ The intensity of the asymmetric stretching vibration peak (-C ≡ C-stretching vibration peak is also in the area, but the intensity is small) is obviously changed, the curing process of the resin can be accurately reflected, and the curing reaction degree alpha is calculated by the following formula:

in the formula, a ₀ And a _{0 mark} respectively-N before the resin curing reaction ₃ and-C = C-peak area of absorption peak; a is _t And a _{T mark} Respectively, at time t, a certain stage of the resin curing reaction-N ₃ and-C = peak area of absorption peak of C-. The results of the quantitative analysis are shown in Table 1.

TABLE 1 degree of cure of mPTA resins

Note: the meanings of "0 to 4" in table 1 are the same as those of "0 to 4" in fig. 4.

As can be seen from the table, the mPTA resin has a curing reaction degree of 77% after reacting at 80 ℃ for 12 hours, which indicates that the mPTA resin has low-temperature curing characteristics. The temperature is continuously raised, the temperature is kept at 120 ℃ for 2h, and the temperature is kept at 150 ℃ for 2h, so that the curing reaction degree can reach 98 percent. On the basis, after the temperature is continuously raised to 180 ℃ for two hours of reaction, the curing reaction degree tends to be complete.

After removing the solvent from the brown liquid prepared in the step (2), the rheological curve of the resin is tested. FIG. 5 is a rheological curve of the polytriazole resin synthesized in example 1, and it can be seen from FIG. 5 that the resin of the present invention has a wide processing window, ranging from 36 to 102 ℃.

The mPTA resin (after solvent removal) can be easily dissolved in acetone, THF, chlorohydrocarbon solvent and strong polar solvent such as DMF, DMSO, etc.

FIG. 6 is a DSC plot of the polytriazole-containing resin synthesized in example 1 with the upward arrows indicating the exotherm. DSC analysis (10 deg.C/min, nitrogen) showed that the resin could be cured at 60-180 deg.C.

The brown liquid mPTA resin prepared in the embodiment 1 is subjected to solvent removal, then is subjected to heat preservation at 80 ℃ for 12 hours for molding, and then is subjected to heat preservation at 120 ℃ for 2 hours, at 150 ℃ for 2 hours and at 180 ℃ for 2 hours in sequence for complete curing to obtain a dark brown hard resin cured product (the density is 1.2263 g/cm) ³ ) The resin cured was tested for DMA and TGA curves. FIG. 7 is a DMA curve of a cured product of the polytriazole resin with benzene synthesized in example 1. T is determined by DMA analysis (double cantilever) _g It was 251 ℃. FIG. 8 is a TGA curve of a cured product of the polytripolytriazole-containing resin synthesized in example 1 under nitrogen, wherein the dotted line represents 5wt% of the thermal weight loss of the cured product. As can be seen from FIG. 8, TGA analysis (10 ℃/min, nitrogen) measured the 5% thermogravimetric temperature T of the cured product _d5 The temperature was 360 ℃.

The crosslink density of the mPTA resin can be estimated using the following formula.

Wherein E' is T = T _g Storage modulus at +40, R is the gas constant, γ is the Poisson's ratio, for an incompressible network, assumed to be 0.5,d _c Is the crosslink density (mol/cm) of the resin ³ ). The calculation result was 6.92X 10 ^-3 mol/cm ³ 。

A cured resin casting was prepared from the brown liquid resin obtained in example 1, and the cured resin casting was prepared by the following method: firstly, polishing a casting body mould, and uniformly spraying a release agent on the surface of the mould; then placing the mold inPreheating for 1h in a vacuum oven at 80 ℃. The brown liquid resin was poured into a mold and after the resin melted, it was held under vacuum for about 2 hours to remove air and solvent until no air bubbles appeared within 12 seconds, and then transferred to a high temperature oven for curing. The curing process comprises the following steps: the mixture is molded after heat preservation for 12 hours at 80 ℃, and then is completely cured after heat preservation for 2 hours at 120 ℃,2 hours at 150 ℃ and 2 hours at 180 ℃. And (5) demolding after curing is finished, and polishing the sample bar to a test standard size. Bending property test specimen size: 80X 15X 4mm ³ . The bending property of the cured resin casting body is tested by a three-point bending test method, and the result shows that the bending strength is 122.3MPa and the bending modulus is 2.7GPa.

Example 2 preparation of T700 unidirectional carbon fiber/mPTA resin composite

The mPTA prepared in example 1 was dissolved in acetone to prepare a resin sol solution having a solid content of 35 wt%. Soaking T700 carbon fiber (Nippon Dongli T700SC type) in glue, arranging, air drying, and cutting into 13 × 10cm ² And (2) taking 12 layers of prepregs to be tidily stacked together in a rectangle with the size, placing the rectangle on a flat vulcanizing machine, firstly preserving heat for 12 hours at 80 ℃ under the pressure of 0.8MPa to form the rectangle, then preserving heat for 2 hours at 120 ℃,2 hours at 150 ℃ and 2 hours at 180 ℃ under normal pressure in sequence, completely curing, and pressing the rectangle into a plate with the thickness of 2mm, wherein the size of the plate is 13cm multiplied by 10cm multiplied by 2cm.

Example 2 mechanical properties of the resin composite material were measured by a three-point bending method (normal temperature test temperature), and the specific test results were as follows: the flexural strength was 1454MPa, the flexural modulus was 143.5GPa, and the interlaminar shear strength was 50.55MPa.

Example 3

In this example, except that the molar ratio of alkynyl to azido was 1.05, the parameters and conditions were the same as in example 1, and a corresponding brown liquid mPTA resin was prepared.

The properties of the mPTA resin obtained in example 3 are comparable to those of the mPTA resin obtained in example.

Example 4

In this example, parameters and conditions were the same as in example 1 except that the molar ratio of alkynyl group to azido group was 1.10.

The properties of the mPTA resin obtained in example 4 are comparable to those of the mPTA resin obtained in example.

Claims

1. The polytriazole resin containing the polyphenyl is characterized by being a copolymer prepared by performing 1, 3-dipolar cycloaddition reaction on tetra- (4-propargyloxystyrene) ethylene and 4,4' -biphenyl dimethyl azide;

wherein the structural formula of the tetra- (4-propargyloxystyrene) ethylene is shown as follows:

the molar ratio of alkynyl to azido is (1.0-1.30): 1.0.

2. The polytriazole resin of claim 1, wherein the molar ratio of the alkynyl groups to the azido groups is (1.02-1.10): 1.0;

and/or the structure of the poly-benzene-containing polytriazole resin is shown as the formula I:

wherein the content of the first and second substances,

3. the polytriazole resin of claim 1, wherein the molar ratio of the alkynyl groups to the azido groups is 1.02.

4. The polybenzazole resin according to claim 1,characterized in that the glass transition temperature T of the cured product of the polytripolytriazole-containing resin is _g Is 250 to 255 ℃;

and/or the processing window of the poly-triazole resin containing the polyphenyl is 36-102 ℃;

and/or the density of the polyphenyl-containing polytriazole resin after complete curing is 1.2-1.3 g/cm ³ ；

And/or the crosslinking density of the polyphenyl-containing polytriazole resin after complete curing is 6.9-7.0 x 10 ^-3 mol/cm ³ ；

And/or, the condensate of the polyphenyl-containing polytriazole resin has 5wt% thermal weight loss temperature T _d5 Can be 360-365 ℃.

5. A process for preparing the polytriazole resin according to any one of claims 1 to 4, which comprises the steps of:

1) Under the conditions of alkaline condition and existence of water-soluble organic solvent, reacting tetra- (4-hydroxybenzene) ethylene with bromopropyne to obtain the tetra- (4-propargyloxybenzene) ethylene;

the structural formula of the tetra- (4-hydroxystyrene) ethylene is as follows:

6. The method for preparing the polytriazole resin with polyacene according to claim 5, wherein in the step 1), the basic condition is achieved by adding one or more of potassium carbonate, sodium carbonate and sodium hydroxide;

and/or, in the step 1), the organic solvent is DMAc and/or DMF;

and/or in the step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the alkali used under the alkaline condition is 1.0 (4.0-8.0);

and/or in the step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the bromopropyne is 1.0 (4.2-5.2);

and/or, in the step 1), after the bromopropyne is added dropwise at normal temperature, carrying out the reaction;

and/or in the step 1), the reaction temperature is 60-80 ℃;

and/or in the step 1), the reaction time is 20-30 h;

and/or, in the step 1), after the reaction is finished, carrying out post-treatment; the post-treatment operation is carried out according to the following steps: after removing excessive salt, standing the obtained filtrate in water for precipitation, filtering to obtain a crude product, and recrystallizing the crude product.

7. The method for preparing the polythenyl-containing polytriazole according to claim 5, wherein in step 1), said basic conditions are achieved by adding potassium carbonate;

and/or, in step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the base used under basic conditions is 1.0;

and/or, in step 1), the molar ratio of the tetra- (4-hydroxystyrene) ethylene to the bromopropyne is 1.0;

and/or, in step 1), the temperature of the reaction is 70 ℃;

and/or, in the step 1), the reaction time is 24h.

8. The method for preparing the polythenyl-containing polytriazole resin according to claim 5, wherein in step 2), said organic solvent is acetone and/or THF;

and/or in the step 2), the total mass of the tetra- (4-propargyloxystyrene) and the 4,4' -biphenyl dimethyl azide accounts for 25-50% of the total mass of the reaction liquid;

and/or, in the step 2), the reaction conditions are as follows: the temperature is 60-70 ℃, and the time is 1-6 h;

and/or, in the step 2), after the reaction result is obtained, cooling the reaction liquid to room temperature.

9. The process for producing the polytriazole resin with a poly-benzene according to claim 5,

in the step 2), the total mass of the tetra- (4-propargyloxystyrene) and the 4,4' -biphenyl dimethyl azide accounts for 50 percent of the total mass of the reaction solution;

and/or, in the step 2), the reaction conditions are as follows: the temperature is 70 ℃ and the time is 1.5h.

10. A polytriazole resin composite material containing polyacene, characterized in that the polytriazole resin containing polyacene is used as a raw material for the composite material according to any one of claims 1 to 4.

11. The preparation method of the polyphenyl-containing polytriazole resin composite material is characterized by comprising the following steps of:

1) Impregnating reinforcing fibers with a solution containing the polytriazole resin according to any one of claims 1-4 to obtain a prepreg;

2) And removing the solvent from the prepreg, and carrying out die pressing, curing and forming to obtain the polyphenyl-triazole-containing resin composite material.

12. The method for preparing the polyterphenyl polytriazole resin composite material as claimed in claim 11, wherein in step 1), the concentration of said polyterphenyl polytriazole resin in said solution is 35-40 wt%;

and/or, in the step 1), the solvent adopted in the solution is tetrahydrofuran and/or acetone;

and/or, in the step 1), the reinforcing fiber is carbon fiber or quartz fiber;

and/or in the step 2), the temperature for mould pressing, curing and forming is 80-200 ℃;

and/or in the step 2), the time for mould pressing, curing and forming is 12-18 h;

and/or in the step 2), the pressure of the mould pressing, curing and forming is 0.6-1 MPa.

13. The method for producing a polybenzazole resin composite according to claim 12,

in the step 1), the reinforced fiber is unidirectional carbon fiber T700;

and/or in the step 2), the temperature of the mould pressing, curing and forming is 80 ℃,120 ℃, 150 ℃ or 180 ℃;

and/or in the step 2), the pressure for mould pressing, curing and forming is 0.8MPa.

14. The method for preparing the polytriazole resin composite material with polyazole according to claim 12, wherein in the step 2), the step of molding is performed by curing at 70-80 ℃ and then completely curing at 120-180 ℃.

15. The method for preparing the polytriazole resin composite material with polyphenyl according to claim 12, wherein in the step 2), the step of mold pressing, curing and forming includes that the material is formed by keeping the temperature of 80 ℃ for 12 hours under the pressure of 0.8MPa, and then the material is cured completely by keeping the temperature of 120 ℃ for 2 hours, keeping the temperature of 150 ℃ for 2 hours and keeping the temperature of 180 ℃ for 2 hours under normal pressure.

16. A polybenzazole resin composite obtained by the process according to any one of claims 11 to 15.